import sys
from time import sleep
import pygame
from bullet import Bullet
from alien import Alien


def check_keydown_events(event, ai_settings, screen, ship, bullets):
    """响应按键"""
    if event.key == pygame.K_RIGHT:
        # 向右移动飞船
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_q:
        sys.exit()


def fire_bullet(ai_settings, screen, ship, bullets):
    """如果还没有达到限制，就发射一颗子弹"""
    # 创建一颗子弹，并将其加入到编组bullets中
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)


def check_keyup_events(event, ship):
    """响应松开"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False


def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
    """响应按键和鼠标事件"""
    # 每当用户按键时，都将在Pygame中注册一个事件。
    # 事件都是通过方法pygame.event.get()获取的
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens,
                              bullets, mouse_x, mouse_y)
        # 每次按键都被注册为一个KEYDOWN事件。
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, ship, bullets)
        # 松开按键时则设置为 False
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)


def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens,
                      bullets, mouse_x, mouse_y):
    """在玩家单击Play按钮时开始新游戏"""
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    # 只有当玩家单击了play按钮且游戏当前处于非活动状态时，游戏才开始
    if button_clicked and not stats.game_active:
        # 重置游戏设置
        ai_settings.initialize_dynamic_settings()

        # 隐藏光标,让光标位于游戏窗口时将其隐藏起来
        pygame.mouse.set_visible(False)

        # 重置游戏统计信息
        stats.reset_stats()
        # 设置为True,这样函数执行完后，游戏就会开始
        stats.game_active = True

        # 重置记分牌图像
        sb.prep_score()
        sb.prep_high_score()
        sb.prep_level()
        sb.prep_ships()

        # 清空外星人列表和子弹列表
        aliens.empty()
        bullets.empty()

        # 创建一群新的外星人，并让飞船居中
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()


def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):
    """更新屏幕上的图像，并切换到新屏幕"""
    # 每次循环时都重绘屏幕
    screen.fill(ai_settings.bg_color)
    # 在飞船和外星人后面重绘所有子弹
    for bullet in bullets.sprites():
        bullet.draw_bullet()
    ship.blitme()
    aliens.draw(screen)

    # 显示得分
    sb.show_score()

    # 如果游戏处于非活动状态，就绘制Play按钮
    if not stats.game_active:
        play_button.draw_button()

    # 让最近绘制的屏幕可见
    pygame.display.flip()


def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """更新子弹的位置，并删除已消失的子弹"""
    # 更新子弹的位置
    bullets.update()
    check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens,
                                  bullets)


def check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens,
                                  bullets):
    # 检测是否有子弹击中了外星人
    # 如果是这样，就删除相应的子弹和外星人
    collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)

    if collisions:
        for aliens in collisions.values():
            stats.score += ai_settings.alien_points * len(aliens)
            sb.prep_score()
        stats.score += ai_settings.alien_points
        check_high_score(stats, sb)
        sb.prep_score()

    if len(aliens) == 0:
        # 删除现有的子弹,加快游戏节奏，并新建一群外星人
        bullets.empty()
        ai_settings.increase_speed()

        # 提高等级
        stats.level += 1
        sb.prep_level()

        create_fleet(ai_settings, screen, ship, aliens)

    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)


def check_fleet_edgs(ai_settings, aliens):
    """有外星人到达边缘时采取相应的措施"""
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break


def change_fleet_direction(ai_settings, aliens):
    """将整群外星人下移，并改变它们的方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1


def ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets):
    """响应被外星人撞到的飞船"""
    if stats.ships_left > 0:
        # 将ship_left-=1
        stats.ships_left -= 1

        # 更新记分牌
        sb.prep_ships()

        # 清空外星人列表和子弹列表
        aliens.empty()
        bullets.empty()

        # 创建一群新的外星人，并将飞船放到屏幕底端中央
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

        # 暂停
        sleep(0.5)

    else:
        stats.game_active = False
        pygame.mouse.set_visible(True)


def check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets):
    """检查是否有外星人到达了屏幕底端"""
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            # 像飞船被撞到一样处理
            ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)
            break


# def check_aliens_bottom(ai_settings,stats,screen,sb,ship,aliens,bullets):
#     """检查是否有外星人到达了屏幕底端"""
#     screen_rect=screen.get_rect()
#     for alien in aliens.sprites():
#         if alien.rect.bottom>=screen_rect.bottom:
#             #像飞船被撞到一样处理
#             ship_hit(ai_settings,stats,screen,sb,ship,aliens,bullets)
#             break
def update_aliens(ai_settings, stats, screen, sb, ship, aliens, bullets):
    """检查是否有外星人位于屏幕边缘，更新外星人群中所有外星人的位置"""
    check_fleet_edgs(ai_settings, aliens)
    aliens.update()
    # 检查是否有外星人到达屏幕底端
    check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets)

    # 检测外星人和飞船之间的碰撞
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)


def get_number_aliens_x(ai_settings, alien_width):
    """计算每行可以容纳多少外星人"""
    available_space_x = ai_settings.screen_width - 2 * alien_width
    number_aliens_x = int(available_space_x / (2 * alien_width))
    return number_aliens_x


def get_number_rows(ai_settings, ship_height, alien_height):
    """计算屏幕可以容纳多少行外星人"""
    available_space_y = (ai_settings.screen_height -
                         (3 * alien_height) - ship_height)
    number_rows = int(available_space_y / (2 * alien_height))
    return number_rows


def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    """创建一个外星人，并将其放在当前行"""
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 2 * alien_width * alien_number
    alien.rect.x = alien.x
    alien.rect.y = 2 * alien.rect.height + 1.5 * alien.rect.height * row_number
    aliens.add(alien)


def create_fleet(ai_settings, screen, ship, aliens):
    """创建外星人群"""
    # 创建一个外星人，并计算一行可以容纳多少个外星人
    alien = Alien(ai_settings, screen)
    number_aliens_x = get_number_aliens_x(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height,
                                  alien.rect.height)

    # 创建外星人群
    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            create_alien(ai_settings, screen, aliens, alien_number,
                         row_number)


def check_high_score(stats, sb):
    """检查是否诞生了新的最高得分"""
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()

# 下面这段代码中含有错误
# def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets,
#                   play_button):
#     """更新屏幕上的图像，并切换到新屏幕"""
#     # 用背景色填充屏幕
#     screen.fill(ai_settings.bg_color)
#     # 在飞船和外星人后面重绘所有子弹
#     for bullet in bullets.sprites():
#         bullet.draw_bullet()
#     # 每次循环时都重绘屏幕
#     ship.blitme()
#     # alien.blitme()
#     # 对编组调用draw()时，Pygame自动绘制编组的每个元素，
#     # 绘制位置由元素的属性rect决定。
#     # 在这里，aliens.draw(screen)在屏幕上绘制编组中的每个外星人。
#     aliens.draw(screen)
#
#     # 显示得分
#     sb.show_score()
#
#     # 如果游戏处于非活动状态，就绘制play按钮
#     if not stats.game_active:
#         play_button.draw_button()
#
#     # 让最近绘制的屏幕可见
#     pygame.display.flip()
#
#
# def update_bullets(ai_settings, screen, stats, sb,
#                    ship, aliens, bullets):
#     """更新子弹的位置，并删除已消失的子弹"""
#     # 下面一行将为编组bullets中的每颗子弹调用bullet.update()
#     bullets.update()
#     # 删除已经消失的子弹,在这里遍历的是编组的副本，并在原始编组中
#     # 删除已经消失的子弹。
#     # 这样操作的原因是。这是因为在 Python 中在迭代过程中
#     # 修改集合（比如列表、集合、字典）是不安全的，
#     # 因为这会导致迭代过程中的未定义行为。
#     for bullet in bullets.copy():
#         if bullet.rect.bottom <= 0:
#             bullets.remove(bullet)
#     # 显示当前还有多少子弹
#     # print(len(bullets))
#
#     check_bullet_alien_collisions(ai_settings, screen, stats, sb,
#                                   ship, aliens, bullets)
#
#
# def check_bullet_alien_collisions(ai_settings, screen, stats, sb,
#                                   ship, aliens, bullets):
#     # 检查是否有子弹击中了外星人
#     # 新增的这行代码遍历编组bullets中的每颗子弹，
#     # 再遍历编组aliens中的每个外星人。
#     # 每当有子弹和外星人的rect重叠时，
#     # groupcollide()就在它返回的字典中添加一个键-值对。
#     # 两个实参True告诉Pygame删除发生碰撞的子弹和外星人。
#     # （要模拟能够穿行到屏幕顶端的高能子弹——消灭它击中的每个外星人，
#     # 可将第一个布尔实参设置为False，并让第二个布尔实参为True。
#     # 这样被击中的外星人将消失，但所有的子弹都始终有效，
#     # 直到抵达屏幕顶端后消失。）
#     collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)
#     if collisions:
#         for aliens in collisions.values():
#             stats.score += ai_settings.alien_points * len(aliens)
#             sb.prep_score()
#         stats.score += ai_settings.alien_points
#         check_high_score(stats, sb)
#         sb.prep_score()
#
#     if len(aliens) == 0:
#         # 如果整群的外星人被消灭，删除现有的子弹，加快游戏节奏，并创建一群新的外星人
#         bullets.empty()
#         ai_settings.increase_speed()
#
#         stats.level += 1
#         sb.prep_level()
#
#         create_fleet(ai_settings, screen, ship, aliens)
#
#
# def create_fleet(ai_settings, screen, ship, aliens):
#     """创建外星人群"""
#     # 创建一个外星人，并计算一行可容纳多少个外星人
#     # 外星人间距为外星人宽度
#     alien = Alien(ai_settings, screen)
#     number_aliens_x = get_number_aliens_x(ai_settings, alien.rect.width)
#     number_rows = get_number_rows(ai_settings, ship.rect.height,
#                                   alien.rect.height)
#
#     # 创建外星人群
#     for row_number in range(number_rows):
#         for alien_number in range(number_aliens_x):
#             create_alien(ai_settings, screen, aliens,
#                          alien_number, row_number)
#
#
# def get_number_aliens_x(ai_settings, alien_width):
#     """计算每行可以容纳多少个外星人"""
#     # 计算可用于放置外星人的水平时间，以及其中可容纳多少个外星人
#     available_space_x = ai_settings.screen_width - 2 * alien_width
#     # 使用int()确保计算得到的外星人数量为整数
#     number_aliens_x = int(available_space_x / (2 * alien_width))
#     return number_aliens_x
#
#
# def get_number_rows(ai_settings, ship_height, alien_height):
#     """计算屏幕可容纳多少行外星人"""
#     available_space_y = (ai_settings.screen_height -
#                          (3 * alien_height) - ship_height)
#     number_rows = int(available_space_y / (2 * alien_height))
#     return number_rows
#
#
# def create_alien(ai_settings, screen, aliens, alien_number, row_number):
#     # 创建一个外星人并加入当前行
#     alien = Alien(ai_settings, screen)
#     alien_width = alien.rect.width
#     alien.x = alien_width + 2 * alien_width * alien_number
#     alien.rect.x = alien.x
#     alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
#     # alien.rect.y = 2 * alien.rect.height + 1.5 * alien.rect.height * row_number
#     aliens.add(alien)
#
#
# def change_fleet_direction(ai_settings, aliens):
#     """将整群外星人下移，并改变他们的方向"""
#     for alien in aliens.sprites():
#         alien.rect.y += ai_settings.fleet_drop_speed
#         ai_settings.fleet_direction *= -1
#
#
# def check_fleet_edgs(ai_settings, aliens):
#     """有外星人到达边缘时应该采取的相应的措施"""
#     for alien in aliens.sprites():
#         if alien.check_edges():
#             change_fleet_direction(ai_settings, aliens)
#             break
#
#
# def ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets):
#     """响应被外星人撞到的飞船"""
#     if stats.ships_left > 0:
#         stats.ships_left -= 1
#
#         # 更新记分牌
#         sb.prep_ships()
#
#         # 清空外星人列表和子弹列表
#         aliens.empty()
#         bullets.empty()
#
#         # 创建一群新的外星人，将飞船放到屏幕底端中央
#         create_fleet(ai_settings, screen, ship, aliens)
#         ship.center_ship()
#
#         sleep(0.5)
#     # 游戏结束，光标可见
#     else:
#         stats.game_active = False
#         pygame.mouse.set_visible(True)
#
#
# def check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets):
#     """检查是否有外星人到达了屏幕底端"""
#     screen_rect = screen.get_rect()
#     for alien in aliens.sprites():
#         if alien.rect.bottom >= screen_rect.bottom:
#             # 像飞船被撞到一样进行处理
#             ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)
#             break
#
#
# def update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets):
#     """检查是否有外星人位于屏幕边缘，并更新外星人群中所有外星人的位置"""
#     check_fleet_edgs(ai_settings, aliens)
#     aliens.update()
#     # 检查是否有外星人到达屏幕底端
#     check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets)
#
#     # 检测外星人和飞船之间的碰撞
#     if pygame.sprite.spritecollideany(ship, aliens):
#         # print("Ship hit!!!")
#         ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)
#
#
# def check_high_score(stats, sb):
#     """检查是否诞生了新的最高得分"""
#     if stats.score > stats.high_score:
#         stats.high_score = stats.score
#         sb.prep_high_score()

# coding=gbk


#
#
# def check_keyup_events(event, ship):
#     """响应松开"""
#     if event.key == pygame.K_RIGHT:
#         ship.moving_right = False
#     elif event.key == pygame.K_LEFT:
#         ship.moving_left = False
#
#
# def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
#     """响应按键和鼠标事件"""
#     for event in pygame.event.get():
#         if event.type == pygame.QUIT:
#             sys.exit()
#
#         elif event.type == pygame.KEYDOWN:
#             check_keydown_events(event, ai_settings, screen, ship,
#                                  bullets)
#         elif event.type == pygame.KEYUP:
#             check_keyup_events(event, ship)
#         elif event.type == pygame.MOUSEBUTTONDOWN:
#             mouse_x, mouse_y = pygame.mouse.get_pos()
#             check_play_button(ai_settings, screen, stats, sb, play_button,
#                               ship, aliens, bullets, mouse_x, mouse_y)
#
#
# def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens,
#                       bullets, mouse_x, mouse_y):
#     """在玩家单击Play按钮时开始游戏"""
#     button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
#     if button_clicked and not stats.game_active:
#         # 重置游戏设置
#         ai_settings.initialize_dynamic_settings()
#
#         # 隐藏光标
#         pygame.mouse.set_visible(False)
#
#         # 重置游戏统计信息
#         stats.reset_stats()
#         stats.game_active = True
#
#         # 重置记分牌图像,显示等级，显示剩余飞船数
#         sb.prep_score()
#         sb.prep_high_score()
#         sb.prep_level()
#         sb.prep_ships()
#
#         # 清空外星人列表和子弹列表
#         aliens.empty()
#         bullets.empty()
#
#         # 创建一群新的外星人，并让飞船居中
#         create_fleet(ai_settings, screen, ship, aliens)
#         ship.center_ship()
#
#
